PITTSBURGH — There were a number of reasons why the Rangers overcame a 3-1 series deficit to beat the Penguins in Game 7 on Tuesday night.

Their goalie, Henrik Lundqvist is at the top of that list. Not far behind was the emotional bonding that took place after Martin St. Louis’ mother passed away last week, St. Louis’ return to the team providing immeasurable motivational power.

But don’t overlook the work the Rangers did against Sidney Crosby and Evgeni Malkin, the Penguins’ two powerhouse goal scorers.

Tuesday night might have been the peak defensive performance of the series on the two snipers. Crosby finished with only two shots in 22:02 minutes of ice time, and Malkin had four shots in 23:04 minutes on a night Penguins coach Dan Bylsma opted to split the two from the line they’d been playing on together.

Neither scored. Neither, in fact, was a factor in the final three games the Rangers swept after falling behind 3-1.

“Collectively, a big key to the series we talked about was stopping the big guns they have,’’ Rangers defenseman Ryan McDonagh said. “With the talent and skill they have, you’ve got to do your best to bump them and disrupt them, not give them time and space.

“We had been giving them a lot of space, being a little too careful and conservative, and after Game 4 we decided to play them with some more edge and more feistiness, and it allowed us use our legs to get in on the forecheck and get in more on the offense zone.’’

Defenseman Marc Staal was a key to disrupting Crosby, roughing him up a number of times in the last three games.

“They’re two of the best players in the league offensively, and as a team we did a great job,’’ Staal said. “It wasn’t one or two guys that were on them when they were on ice. They weren’t getting into their rhythm that they love so much in neutral zone.

“It was a Game 7 and you want to shut down their best players. When they’re buzzing and confident and making plays they are not an easy two to stop.’’

Crosby finished the series with only one goal and two assists. Malkin had three goals and three assists.

“I’d love to tear it up every series,” Crosby said. “But it’s not always the case. When you’re not able to contribute as much as you’d like, it’s tough. Obviously, I would have liked to score more, contribute more. It wasn’t a lack of effort or competing. But it doesn’t make it any easier, I’ll tell you that.”